The present invention relates to an adjusting device, more particularly, to an adjusting device for controlling switch which generally comprises a transmission mechanism and an adjusting mechanism. The gear of the transmission mechanism is meshed with a driving gear and a worm is driven via an inner gear. The worm is further meshed with a driven gear of the adjusting mechanism. The driven gear is provided with clutching plates at both sides. A stopping block biased by a resilient spring plate is disposed adjacent to the clutching plate such that the clutching plate is pressed against the driven gear and is rotated together with the driven gear. The clutching plate is provided with a coil spring externally and centrally. The resilient spring plate is further provided with a triggering rod such that the clutching plate can be removed from the driven gear. On the other hand, the clutching plate can be also moved back to its original position by the coil spring such that the stopping block will press onto a rocker arm and the switch will be triggered off. The stopping block can be readily adjusted such that the driving mechanism can be readily triggered off in both clockwise and counterclockwise rotation.